1. Field of Invention
This invention is concerned with the lubricating oil composition used in gas turbine or jet engines. Gas turbine engines are operated under extreme environmental conditions. The lubricant must be fluid at extremely low temperatures and must be an effective lubricant in an engine which produces internal engine temperatures in the range of 450.degree.-500.degree. F. or above. These operating conditions put severe stresses on the lubricating oil, so much so that the most advanced mineral lubricating oil compositions cannot be employed in gas turbine engines.
Currently, synthetic ester base lubricating oil compositions containing a critically balanced blend of additives are being effectively employed for lubricating gas turbine engines. These ester base oils are operative over a wide temperature range and exhibit high thermal stability, anti-wear, load-carrying and anti-oxidation properties while providing good lubrication.
With the advent of newer and more powerful gas turbine engines designed to provide advanced levels of supersonic flight, higher levels of thermal and oxidative stresses are imposed on the lubricating oil. It is also important to reduce or prevent metal staining and corrosion by the oil composition.